In August 2014, RBI revised the limits of Free ATM transactions. Here is a piece from one of the newspaper "Frequent withdrawal of money from ATMs will become expensive from November, with the RBI imposing a limit of 3 transactions per month from ATMs of other banks and 5 from the same bank in six metropolitan cities.

A customer will be required to pay a fee of up to Rs 20 for using Automated Teller Machines (ATMs) beyond the permitted numbers of transactions in Delhi, Mumbai, Chennai, Bangalore, Kolkata and Hyderabad."

So, we can say that in city like Bangalore you can do upto 3 free transactions in ATM of other banks and 5 free transactions in the ATM of card holders bank.

Now you can do minimum 3 transactions (financial or non-financial) free of charge in a month at other bank ATMs locted in metro cities (Delhi, Mumbai, Chennai, Kolkata, Bengalore & Hyderabad) and at other locations minimum 5 Transactions per month.

And you can do minimum 5 transactions in a month free of charge at own bank ATMs irrespective of location of ATMs.

However, Banks on their own can decide to offer more number of transactions free of cost to their customers.

Beyond the limit you can be charged at maximum of Rs. 20 (plus service tax, if any) per transactions.